In the Beginning
by DAWNWRIGHTER
Summary: SN, Percy Jackson and Nasuverse crossover. The Mage Association is after a 10 year old Sam Winchester knowing about the demon blood in his veins, and they have hired the Magus Killer Kiritsugu Emiya to bring him to them. Dean, John, and Bobby refuse to let Him or those Monsters have him. Even if they die trying. MagusWinchesters! FemCas (no slash) future Destiel. Massively AU
1. Chapter 1

**A/N Supernatural, Nasuverse, and Percy Jackson crossover! I own none of these franchises and honestly wish I could.**

 **I've always thought that these universe would go very well together, for their similar concepts and tone.**

 **Enjoy!**

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 _In The Beginning._

 _God, my father created the Universe, its sibling Destruction (Darkness) tried to destroy it, just like it did quadrillions of times before. The Darkness did this because this was its job to Destroy. For you see they were nothing but concepts in the very very beginning, The Darkness concept of destruction, my Father's concept of creation. They were both born in the inevitable creation of something OTHER than nothing, and since the Creation of something other than Nothing means the Destruction of Nothing for there in fact is SOMETHING, meant we were both born at exactly the same time…._

 _Because of this we know not who was born first Creation or Destruction. But eventually these concepts clash and they would clash endlessly for the concepts could not destroy each other. For Creation would have to destroy Destruction by creating, and Destruction destroy Creation by creating destruction._

 _I guess you could say we were doing nothing but reacting to each other in the beginning. But over time we would form patterns, systems, like a computer we would figure out which way to destroy and build was more efficient, which way lasted longer, was better at doing its job. Over a period of several quadrillion years these systems worked against each other, like evolution these systems grew so complex that they eventually grew personalities, minds, souls._

 _And like the evolution of life on Earth eventually these reactions developed into thinking beings._

 _But one was smarter than the other, because after all creating is harder than destroying, and all that hardship helped ME the Creator to develop a way to create a permanent creation. Putting all of his being, his Soul, his very concept into a single point, and manifested itself into something that not even the Darkness could destroy for it would destroy itself if it did._

 _That didn't mean it didn't try._

 _The Darkness grew angry that it for once in its creation couldn't destroy something, so angry in fact it was willing to destroy itself to and start The Beginning all over again in order to "win" so to speak._

 _But The Light could not fight it alone, for destruction is far easier to deal out than creation is._

 _So The Creator created its first Children, Michael, The Bearer of Darkness, The Archangel of Destruction. Lucifer, The Bearer of Light, The Archangel of Creation. Raphael, The Bearer of Water, The Archangel of Healing, and Gabriel, The Bearer of Fire, The Archangel of Battle._

 _The Creator along with its elder born managed to seal away the Soul, and Mind of the Darkness into the first weapon of ever created._

 _Ea. The Sword of the Beginning._

 _Once the Battle was over the Creator, God, as its Children called it was left severely weakened and was slowly getting weaker, but did not falter when it told its Children to create the rest of the Universe._

 _All of its children were told to stay by God's side as it made its new home, a place in which later Angels would call Heaven, and God taught them both how to create souls from creation and destruction, Light and Dark, like how he himself had done to create his Children._

 _But they were not God, and it took all four of them to create this new being._

 _It had unintended consequences_

 _This being was unlike any other, for it wasn't a being of creation (like God and the Archangels), nor was it a being of destruction but was at an equilibrium, this Being more like a new concept than a thinking individual was rapidly expanding and occupying the new Universe, expanding it and separating heaven from the universes new body. Making the original universe outside of this beings body almost inaccessible to except the most powerful beings._

 _The Archangels named this being Chaos, The Being of Void._

 _The birth of this being was like a domino effect, it's very concept gave birth to a number of different concepts. Time, Death, Light (actual light), Darkness (actual darkness), Gods, Gravity, Physics, Magic, Life, Love, and everything we know in between._

 _Thus the Beginning has ended, and Eternity awaits._

"What the hell you reading Bobby?! Did the Church decide to revise the Bible again?" said a young voice amused. Bobby the man in question jumped what Dead could have sworn was a good couple feet in the and turned to glare over his shoulder at a 12 year old Dean Winchester leaning on the chair he was barely tall enough to see over.

Dean smirks, Bobby snorts agrily. "Fucking little Idjit, scared the shit outta me!" This only makes Dean's smirk wider.

"You must be getting old!" Dean laughs. Bobby just sighs and sits back in his chair. "What you doing up so late ya little jerk?" Dean rubs his arm and Bobby immediately understands. "The Campbell crest still giving you trouble?

Dean shakes his head. "Not as much as it used to, I can use most of the mysteries on it but reinforcement still makes my joints ache."

Bobby just hums in agreement, "Trust me kid your getting the best of it, hehe it gets far worse when you get older"

Dean gets a glint in his eye and starts to smirk.

"So you finally admit you're getting old eh Bobby? Glad to hear your finally accepting it!"

Bobby just groans and heads toward the refrigerator. "I need a drink"

Dean sees his opportunity. "This early? Its 4 am! Man didn't know you were old AND a drunk too!"

"..."

"..."

"You seem to have a lot of energy this morning Dean, should we start training a few hours early?"

"I-I um"

"You know what I think we should." Dean groans. "10 laps from here to town without reinforcement! Then 10 laps with it! Then do your regular drills. You remember your drills right?" Dean nods.

"THEN QUIT STANDING THERE LIKE A LITTLE IDJIT AND GET RUNNING YA SNOT NOSED LITTLE JERK!"

Dean was outta there before the end of the word jerk.

Bobby just stares at the door for a few seconds agrily before softening into a fond smile.

"Little shit's gonna be the death of me…"

Bobby knew it was going to take Dean a few hours to get his running done and so decided to get some sleep before starting his training for the day. He picks up his beer bottles and throws them in a garbage bag hanging on a door handle, then goes and puts away the book he was reading. The book was a good one, though not that great for being basically a fanwork of the Bible, but it was one his wife used to like reading a lot because it didn't have a whole lot of cliches compared to similar fanworks. He put it on the shelf designated as 'Karen's books' and went to bed.

Funny how things that are entirely accurate can get portrayed as fiction because its so far outside of most people grasp on reality.

The title of the book, The Devil's Bible clearly visible on the spine.

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 **A/N Done! I'm not the greatest writer in the world so I hope you all forgive me lol, and I've tried to keep the characters in well character as best as I can (especially Bobby). Im also using this chapter to kind of bridge or merge the universes together. This world will be different and will be a mash between PJ SN and Fate and I hope the passage from the Devil's Bible will help show how even a universe like this one can even come about.**

 **REVIEW I NEED CRITICISM**


	2. Chapter 2

**In the Beginning Chapter 1**

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 **I DON'T own Supernatural, The Riordan Verse, or the Nasuverse, these franchises belong to their companies, authors, and owners.**

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 **Einzbern Castle, Germany, December 28th, 1992, late at night.**

In a secluded area of Germany, close to the Rhine River, stood alone castle painted in otherworldly white. This castle, The Einzbern Castle, was one of the most heavily defended areas on Earth. Located in one of the most inhospitable places in Germany, it was surrounded by powerful bounded fields designed to make any wanderers, whether they be privy to the existence of the Moonlit World or not, give a wide berth. Evil Spirits and packs of hungry wolf packs prowled the forests looking for anyone who roamed to close. Even if one would somehow despite all trials, manage to make it into the Castle without permission they would still have to deal with the legion of artificial nature spirits known as Homunculi, who possess powerful magic circuits that allow them to access more magical energy than most modern Magi. But despite all the potential horrors that lived and breathed around Kiritsugu's and Irisviel's bedroom they were the perfect picture of relaxation. Their daughter Illyasviel, having crawled into bed after a nightmare, was relaxed more so.

The relaxing silence was however ruined by the soft knocking on the bedroom door. Kiritsugu, because of his days as a mercenary, was the only one to hear it. Kiritsugu slowly got out of bed, careful not to wake the other occupants up, and went to answer the door. When he opened the door a young Homunculus in slender maid clothes greeted him with a rapier on her hip, she looked a little intimidated.

"Yes?" Asked Kiritsugu, sounding tired. He looked at her angry for being disrupted from what little sleep he actually gets.

"M-master Emiya…" She stuttered with an ungraceful bow. Kiritsugu raised a black eyebrow, this homunculus was different from most he has seen in the castle.

"M-master Jubstacheit has r-requested your presence in his...u-uh.. s-study…" She stammered, looking away awkwardly. Kiritsugu was definitely sure now she wasn't a normal Einzbern homunculus, they weren't this awkward. Even Iri with all her….ahem…. personality wasn't this awkward. She sounded almost like a child, even though she looked to be in her teens.

She reminded him of Illya in a way. His eyes softened.

"Yeah, sure, lead the wa-"

Before he could finish his sentence, the young homunculus borderline ran out of sight obviously wanting to leave his presence for some reason. "-y once I ...get dressed."

Kiritsugu just shakes his head and sighs. He then gets dressed as silently as possible as to not wake up his wife and daughter. He then goes to leave the room, only stopping to stare at his wife and daughter still fast asleep. He then gives a sigh of longing before closing the door with a quiet, but somehow loud click.

At Jubstacheit's study, two homunculi stood guard with large halberds that were awkward looking with their small womanly bodies. When he approached they didn't even acknowledge him. Kiritsugu stops right in front of them, seeing no reaction or even an awareness of his presence he just snorts and proceeds to enter the office.

"Just machines..." He mumbles.

Jubstacheit's study, which was larger than his by far was also far less spartan. Research papers piled onto every desk, jars filled with unknown liquids and preserved body parts were placed around the room seemingly at random. But by far the strangest thing Kiritsugu was seeing in the room was Old Man Acht fast asleep on his desk with a stupid looking smile on his face with the young homunculus who woke Kiritsugu up standing behind the desk looking even more embarrassed than when he last saw her.

Kiritsugu attempted to wake him by coughing but that proved unsuccessful, he looked towards the homunculus as if asking for her to wake him but just looked away still embarrassed for some reason. Kiritsugu spied a large stack of books by Acht's desk and immediately knew the answer to this weird scenario. Kiritsugu smirked and tipped over the stack of books creating a large crashing sound, the crash definitely had the effect he wanted.

CRASH!

"Bei der Wurzel!" yelled Jubstacheit, eyes wide startled from his sleep. The smirking face of Kiritsugu bringing to surface a massive glare that seemed to brighten the room in a glow.

"My, my old man you probably did the one thing that can make me respect you more." Said Kiritsugu amused.

"And what is that you brat?!" Demanded an enraged Jubstacheit.

Kiritsugu pulled up a chair to the desk and sat down in it, he leaned his elbows on the desk. "You acted human…" Said Kiritsugu like it explained everything.

Acht's glare died down, he then sighed and leaned back into his chair rubbing his tired eyes. "Why are you here my boy?"

Kiritsugu looked at him in confusion. "You summoned me right?"

Acht's eyes widened in realization and he clapped his hands with a grim face. "Ahh yes, I did send Anasviel to get you didn't I?

' _Anasveil is her name?'_ Thought Kiritsugu staring at her. She caught his stare and looked away in an embarrassed blush.

"Well…" Started the older man. "A week ago I received a report from our smuggler in the Archeology Department of the clocktower, in regards for our catalyst for the War."

Acht then stood up and received a piece of parchment from a nearby desk and handed it to Kiritsugu. As Kiritsugu was reading it he continued. "Our friend inside the archeological department team responsible for the locating and acquiring of The Everdistant Utopia has been compromised by one of the higher-ups in the Clock Tower." He said in a grimace. Kiritsugu, however, looked pissed and frustrated.

"How did this happen and why am I only hearing about it now?!"

The Golem looked at him. "A certain vice-director of the clocktower wanted to be there in person when the unearthing of such an important artifact took place." Acht wiggled his hand. " An artifact of this power and significance can't be left to the care and protection mere archeologists and all that." He said sarcastically.

Kiritsugu had a serious look on his face. "Damn…"

Jubstacheit nodded. "Exactly"

Acht then got up and stared out a nearby window, the night pitch black. He grunted. "Despite appearances to the contrary I do in fact care about Irisviel, she is my masterpiece, an almost perfect copy of Justeaze. I don't want to cause her any more emotional pain than she already has to deal with being sacrificed to the grail in little over a year, and I hear from her that dealing with you even in a good mood can be daunting for her sometimes. I wanted to wait until we had no other choice." He explained calmly.

"How kind of you." Kiritsugu snarked. Acht however smiled.

"Fortunately, or ...well, unfortunately, Miss Barthomeloi has given us a way we can be given Avalon as payment." Kiritsugu looked at him curiously.

"Payment? Avalon as payment!? What can be worth more than a 15 hundred-year-old Noble Phantasm from the Fae?"

"Indeed, for a job, she wants us...uh you to do." The old homunculus said calmly.

"Me? She knows I'm here?"

"Well, it's not exactly a secret…" This causes the former freelancer to sigh. "Well then why does she want me for this job? She has hundreds of enforcer agents she can call upon."

"Because you're not connected to the clocktower, and therefore far less likely to be hunted down and killed for just being there." The old man explains.

There? Where was such a place? "Where…?"

"America."

"Ahh..." Is all The Magus Killer says. He rubs his chin. "That makes sense since I'm famous as a freelancer I can stay under the radar of the Scladio family with the guise of a mercenary."

"Which means you can disappear and reappear and do the job without the Family questioning it." Acht nods.

"So what exactly is this job."

"To capture a sealing designate in the States, the designate was located via a source in America and the designate was confirmed by the Observatory." Said Acht matter of factly.

"And who was the source?

"That would be me darling…"

The introduction of a new voice causes both men to widen their eyes in surprise. Anasviel seeing a sudden and unforeseen threat to both men lost her embarrassed gaze drew her rapier, and with inhuman speed and a gust of wind with a boom impaled the intruder with her sword. The supersonic stab barely causes the man to move causing Anasviel's eyes to widen at the lack of a reaction.

The same man disappeared then reappeared away from the shocked homunculus. Anasviel prepared to charge him again but was stopped by the hand of Acht. "Stand down Ana." Ordered Acht.

"B-but master!" A glare from Acht caused her to back down.

The heavyset man proceeds to look at the Rapier buried hilt deep in his heart and looks at the young homunculus. "That really was a good try sweetie, but not good enough I'm afraid.." The man then pulls out the blade like it was just an inconvenience instead of a lethal weapon that just pierced his heart at several times the speed of sound.

"Is this how you treat a guest? Jobs- no Justb- no that's not it either, uh." He fished a piece of paper out of his pocket. "J-U-B-S-T-A-C-H-E-I-T, Yeah that's it. Your name sucks by the way."

Jubstacheit just nods wearily. "Who are you and how did you get in here!?" Asked Kiritsugu in a borderline yell, he was still on edge and had a knife in his hands, he wasn't allowed firearms after all.

Crowley looked the man up and down, obviously satisfied he used his powers to pull up a chair to sit down. "Because your kind and mine don't encounter each other very often Mr. Short and Black." Spoke Crowley as he was sitting down.

Kiritsugu was still standing but a cough and a small glare from Acht managed to get The Magus Killer to put away his weapon and sit down, albeit reluctantly.

Crowley smirked at him. "If it makes you feel any better Mr. Black, that little pig sticker wouldn't have worked on something like me anyway."

"And what….exactly are you?" Asked Acht. 'Maybe if I can get enough information I can update my defenses and fields to stop him and….people... like him from entering my castle.' Then his eyes widened in realization. 'Maybe I can patent it, think of how much money the Einzbern could get?! I could probably expand the castle!' He didn't realize he was drooling.

Crowley looked at him in a deadpan, he looked over to Kiritsugu who was still focused entirely on him. "Is he all right?" He asked Kiritsugu.

Kiritsugu looks over to Acht, sees his face, and looks over back to Crowley with a scowl. "He does that sometimes, but answer the question. What are you?"

Crowley sighs and closes his eyes, only to open them dramatically to show deep blood sclera and irises. "A demon." He states simply with a shrug.

Both Acht and Kiritsugu looked at him in shock. A demon? Demons were very rare in the world, and most demons were very dangerous and unpredictable creatures usually born when a human gains morals or abilities so far outside human nature and ability that the World doesn't recognize them as human anymore, this means this man was either insanely powerful or insanely...well INSANE. They needed to be extremely careful talk-

Before they could finish the thought Crowley got their attention. "I know what your thinking, and I'm not the Insane kind, and I'm not here to kill you either because I'm the source of Little miss Lorelei's information remember? Me and Miss Bossy are partnered in this endeavor and now so are you, Mr. White, and Mr. Black. You get what I'm saying?"

Both men nodded in acceptance, but still on guard. Crowley nodded in approval.

"Then let's get started, boys!" With a snap of his fingers, a small stack of papers appeared in his hand. He threw them on the desk with a loud flap "These are portfolios about your target, and the people he surrounds himself with, look through it at your leisure." He winks at Kiritsugu. "I know you'll get the best use out of this information my little assassin." He pats him on the shoulder and starts to walk away.

"Will you not be joining us, Crowley?" Asks Jubstacheit. Crowley turns back towards them with an apologetic smile. "Unfortunately no I'm quite busy today. I will, however, be back in about a week to transport you to America myself, so Mr. Black make sure you have all the gear you need in order to make this a success. You do have an ancient fairy artifact on the line after all." And with that, he popped out of existence.

When the demon finally left all the occupants of the room finally allowed themselves to lower their guard. That man may not look like that much of a threat but the aura that surrounded him gave them the presence of a being that could kill them all in an instant and knew it.

Jubstacheit looked around the office that got ruined from Anasviel's blitz attack with the demon and sighed. "Look at this mess…" He mumbles.

"I'm s-sorry Master for being so reckless in your s-study." Stuttered the now embarrassed homunculus. Kiritsugu, however, noticed how quickly her personality changed. From a stuttering, embarrassed young teenager to a unhesitating and powerful protector and back again. Her origins were obvious, as were most homunculi of the Einzbern, a failed experiment to recreate the perfect body of the grail Justeaze von Einzbern. But it looks like she has been modified like many of the homunculi of the castle to serve combat purposes, she could fight at supersonic speeds, she was agile, durable, and her sword skills were on par with modern day sword masters.

' _Almost like a Saber Servant…'_

"It's not your fault Ana, you did your job and I can't fault your for that, well done." This causes the embarrassed girl to blush at the praise, happy to have served her master.

Kiritsugu had made up his mind. "Hey Acht?"

Jubstacheit looked over from the piles of paper he was picking up. "Yes my son?"

"I want her to come with me, to America." Kiritsugu said seriously. "Ana, I mean."

The old golem looked over towards Anasviel and saw her shocked expression. "M-me?!" She asked incredulously.

Jubstacheit looked over at her with a raised eyebrow, and nodded. "That's fine with me, more people on the job means it'll be more likely to be a success after all. Anasviel may have been a failed experiment at recreating the Grail Body but she has shown to be adept in combat, take her, you have my blessing."

"She and I will be in my study, studying the notes that demon gave us." Informs Kiritsugu as he makes for the door with Anasviel following him. Old Man Acht nods, still in concentration trying to get the notes back in right order.

When they walk out the door Kiritsugu notices the guards still standing outside the door with their robotic expression on their faces. Kiritsugu smirks. "You guys missed all the action, Anasviel here." He pats her on the shoulder. "Did your job for you." And points inside the open door.

The guards robotic faces turned into ones of comic awe. Awe that they had missed so much and yet heard nothing. This causes Kiritsugu, uncharacteristically one might say, to start laughing out loud, even the usually embarrassed white haired girl started giggling uncontrollably. Their laughter echoing down the hallways of Einzbern Castle.

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 **Singer Salvage Yard, Bobby's House, Sioux Falls, December 27th late evening**

Sam looked down at the black Colt 1911 his father had given a month ago. The room was dark, it was bedtime, and he had been sleeping better with it.

His father had given it to him here, in this house, because he was afraid of the shapes that his mind would conjure in the dark corner that was his closet. "You shouldn't be afraid of the dark Sammy." His father had said. "It should be afraid of you."

When I had originally figured out that the supernatural was real, a year ago, and that Bobby, Dean, Dad, and even MOM were magic users straight out of fiction novels and comics, it excited me to no end. I had begged Bobby and Dean to teach me about magic, to teach me the awesome spells to defeat monsters….

To become a Heroes like the rest of the family….

Fortunately when Bobby had finally unlocked my "Magic Circuits" he discovered that I only had a surprising 19 exceedingly high quality circuits to my name. Even though it was lower than Deans 36 medium quality circuits Bobby said they would "produce similar units of Od" whatever that means.

But me in my childish naive didn't realise how scary and nightmare inducing the Moonlit World could be, but I found out in Oregon that the things that go bump in the night in real life are worse than in fiction. In Oregon at a hotel we were staying at, a ghost would every decade or so kill children that slept on a certain floor, our floor. The ghost, a little girl who was killed by her rapist father, and whose body was stuffed under the floorboards of the closet would repeat the crimes to children of a similar age. It almost got me too, almost to the closet and everything, when Dean came out and banished the ghost temporarily with a old iron pipe from the sink. We made it out alright, but that experienced scarred me. Every time I looked at a closet I saw her face, a child's face that looked like it was rotting.

Sam shivered even in the warmed room. He set down the 1911 on his nightstand, safety off of course, and tried to get some sleep. But he could feel her, in his closet, SHE WAS COMING TO GET HI-! Sam picked up the gun, turned off the safety, and fired his entire magazine at the illusion in his mind. His gun smoke rising, seeing her dead on the ground with half a dozen holes in her body, somehow put his mind at ease, and he went back to sleep. The Sam outside his dream, smiled contently, and snuggled into his pillow.

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 **A/N So we got to see a lot of Kerry, the sometimes awkward Old Man Jubstacheit, an OC Homunculus Anasviel, and a little bit of Sam Winchester.**

 **I hope I made Kiritsugu and Sam into character. Sam had a lot more variety to his character due to the show being Casual, Dramatic, and full of fight scenes. But we don't really see Kiritsugu outside of philosophical arguments, tactical fights, and just basically over all "Assassin mode" very often so I pictured him with my head cannon as an mischievous, sarcastic, and family loving during casual parts of his life like Pre- 4th grail war Kerry.**

 **Also I need a Beta reader, I tried grammarly but it isn't human and can't tell exactly what I want the words to read like.**

 **REVIEW AND CRITIQUE**


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